1. Technical Field
Embodiments of the present invention relate generally to infrared (IR)-based metrology. Specifically, embodiments of the present invention relate to the use of infrared (IR)-based metrology for the detection of stress and effects around through silicon vias (TSVs).
2. Related Art
Thermal-mechanical reliability has become a big concern for the implementation of through silicon vias (TSVs), which are a vital part of 3D integration designs. Specifically, the process-induced stresses due to CTE mismatch between silicon (Si) and copper (Cu) can cause detrimental effects on both the performance and reliability. Such effects include, among other, mobility degradation, Si cracking, device de-bonding, and TSV pop-out.
As such, the measurement and handling of TSV stresses have become an important part of device design and integration. Unfortunately, existing approaches typically require cross-sectioning of the device such as during use of processes such as electron microscopy. That is, microscopy may be limited by either sample surface topography or the requirement of physical damage to the sample being tested.